9 Common Operations
Face and Edge Jointing
The jointer is used for preparing solid wood, making faces flat and true. As solid wood dries from the green (wet) state, it shrinks and changes dimension unequally in the radial and tangential plane. It may have inherent stresses that are released as it it cut to rough size. Face jointing the stock will remove bow, cup and twist from the boards. Edge jointing will straighten the stock, removing crook and kink. Edge jointing will also machine a known angle between the face and edge, for square stock at 90° but also at any angle between 45° and 90° by adjusting the angle of the fence. The face of the board should be jointed first, then the edge can be squared to the face.
Procedure for face jointing
- Determine which face (if any) is concave, it should be placed down on the table. This will be the most stable arrangement, allowing for the piece to be jointed without shifting or rocking on the tables.
- Begin to move the piece into the cutterhead with a hand over hand motion, remembering to lift your hand over the cutterhead and not run it directly over while on the workpiece.
- Apply light pressure on the piece at the start of the cut, enough to keep it in contact with the table. Avoid excessive pressure as this will cause the piece to deflect and spring back after the cut is complete.
- As soon as a sufficient amount of stock is on the outfeed table, transfer the downward pressure to just behind the cutterhead on the outfeed side of the cut. This ensures the part of the stock that was just-cut references the outfeed table. The result will be a flattening of the stock.
- It may take multiple passes to flatten the entire face. The number of passes is determined by the depth of cut per pass, and the amount of defect in the stock.
- Continue jointing until the entire face has been surfaced. Often, listening to the machine will tell you when you have made a full pass.
- With boards with excessive defect such as twist, finesse is required to achieve satisfactory results. The twisted board will have two opposing corners contacting the table, these should be passed over the cutterhead to remove the twist. The piece must be balanced on the two corners while jointing, without rocking.
- You may place paper or veneer shims under the corner not contacting the table at the trailing end of the board to help stabilize it. They will come loose as the end passes over the cutterhead, but do not pose a kickback hazard. Use only thin commercial veneer or paper for this purpose.
Procedure for edge jointing
In most cases, the concave edge is placed down on the machine table for stability. However, in some cases it may be desirable to have the convex edge contacting the table, such as when selecting for grain direction or to remove defects.
- Ensure the fence is set to the desired angle. Use an engineer’s square for 90° or a sliding T bevel or digital inclinometer for angles.
- Place the edge to be jointed on the machine table